Telephone-exchange system



Dec. 29, 1925. 1,568,039

S. B. WILLIAMS. JR., ET AL TELEPHONE EXCHANGE SYSTEM Filed Nov. 6. 1922 14 Sheets-Sheet 1 y My Dec. 29, 1925. 1,568,039

5. B. WILLIAMS, JR., ET AL TELEPHONE EXCHANGE SYSTEM 0 Filed Nov. 8. 1922' 14 Sheets-Sheet 2 Dec. 29, 1925'. 1,568,039

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5. B. WILLIAMS, JR., ET AL TELEPHONE EXCHANGE SYSTEM Filed Nov. 6, 1922 '14 Sheets-Sheet 4 Dec. 29, 1925. 1,568,039

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Dec. 29, 1925- S. B. WILLIAMS, JR.,

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TELEPHONE EXCHANGE SYSTEM 14 Sheets-Sheet 10 m w W m Filed Nov. 6. 1922 [dward f/mr/c/zscw by w/y .Dec. 29, 1925- 1,568,039

s. B. WILLIAMS, JR., ET AL TELEPHONE EXCHANGE SYSTEM Filed'Nov. 6, 1922 14 Sheets-Sheet 11 Q ms Q Dec. 29 1925.

S. B. WILLIAMS, JR., ET AL TELEPHONE EXCHANGE SYSTEM 14 Shee eet 12 Filed Nov. 6, 1922 ang 3% M w\ Q3. 5 Rm 3 Dec. 29 1925' ET AL TELEPHONE EXCHANGE SYSTEM 5. B. WILLIAMS, JR,

Filed Nov. 6. 1922 14 Sheets-Sheet 3 Dec. 29,1925.

5. B. WILLIAMS, JR., ET AL TELEPHONE EXCHANGE SYSTEM QQQ Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

SAMUEL B. WILLIAMS, JR, OF BROOKLYN, AND EDWARD E. HINRICHSEN, OI NEW YORK, N. Y ASSIGNORS TO WESTERN ELECTRIC COMIANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCEL]! GE SYSTEM.

Application filed November 8, 1922. Serial No. 599,182.

To all whom it may concern:

Be it known that we. SAMUEL B. Win- LIAMS, J r., and EDWARD E. HINRICHSEN, cit1- zens of the United States of America, resid- 6 .ing at Brooklyn, in the county of Kings and State of New York, and New York, in the county of New York and State of Ne w York, respectively, have invented certam new and useful Improvements in Telephone- 1 Exchange Systems, of which the following is a full, clear, concise, and exact descrip-v tion. a

This invention relates to telephone exchange systems and more particularly to systems employing automatic switching apparatus for the establishment of conversational connections.

The object of the invention is a system of this character wherein certain equipment subject to frequent use is placed on a common basis thus reducingthe amount of apparatus and increasing the general efiiciency of the system.

A feature of the invention is the provision, in a system having a plurality of groups of circuits, each group accessible to a plurality of switches, ofa common testing mechanism associable with any of said switches for testing any of the groups of circuits.

Another feature relates to the provision of a common set of testing relays and means for connecting said relays to any one of the selector switches for testing and selecting the circuits in any one of said groups.

A further feature relates to the provision, in a system having a plurality of coordinate selector switches each having links for making connection with the trunks of any of a number of groups, of a common testing mechanism connectable to any switch for testing the links thereof and the trunks of any of said groups thereon.

Further features and advantages of this invention will become apparent from the following description and from the appended claims.

Referring to the drawing, Figs. 1 to 14, inclusive, when arranged in the order illustrated in Fig. discloses a suflicient portion of a telephone exchange system wherein the features of the invention are incorporated to enable a thorough understanding thereof.

Fig. 1 diagrammatically illustrates a line switch of the'coor'dinate type in which the subscribers ,line'sterminate and also one of a number of trunks outgoing to a district selector switch. I

Fig. 2 shows in diagram, a coordinate sender selector switch.

Figs. 3 and 4 show one of a. number of common register senders. Fig. 3 illustrates the impulse receivin mechanism, including a set of counting re ays, and Fig. 4 shows four numerical relay registers.

Fig. 5 discloses a district selector switch of the coordinate type in which terminate the trunks incoming from the line switches.

Fig. 6 illustrates a second district selector switch acting in the same capacity as the switch shown in Fig. 5 and having access to the same groups of outgoing trunks.

Fig. 7 represents a relay connector for connecting the register senders to a common district marker.

In the upper left hand corner of Fig. 8 and in Figs. 9 and 10, there is shown the district marker or selection controlling mechanism which is common to a plurality of district selector switches.

Fig. 11 illustrates a multi-contact relay connector for associating the district marker with the several district selector switches.

Fig. 12 shows diagrammatically a group selector switch in which terminate the trunks incoming from the district selectors.

Fig. 13 shows a coordinate connector switch for completing connections to the subscribers lines.

In Fig. 14 and in the upper part of Fig. 8, there is shown a common line marker or selection controlling mechanism for determining theselective operations of the group selector and connector switches.

In the lower half of Fig. 8, there is illustrated, a relay connector device for connecting the register senders to the common line marker.

General description of the system and apparatus.

The telephone system hereindisclose'd employs an'improved form of switchin medium. The line switch 100, the district selector switches 500 and 600, the group selector switch 1200. connector switch 1300, and also the sender selector switch 200 are all of the coordinate type comprising link circuits for the purpose of associating with these trunks any one of the register senders.

Also the trunks outgoing from the line switches appear as incoming trunks in the coordinate district selector switches. There will be a number of these district selectors and each will accommodate a plurality of trunks. In the drawing, two district selectors 500 and 000 are shown and the one trunk illustrated in full, namely trunk 103, appears in the district selector 500 and occupies the vertical row of contacts 501. The second trunk 104 shown outgoing from the line switch 100 may appear in the vertical row 502 of the selector switch 500. Other trunks extending from the line switch 100 may also appear in the switch 500, utilizing other rows of contacts not illustrated. Still other trunks extending from the line switch 100 may appear in other district selector switches as the switch 600. Again, the trunks outgoing from other line switches similar to the switch 100 ma also bedistributed among the district se ectors 500, 600, etc., in any desired manner. Two of the trunks 608 and 609, incoming from line switches and terminating in district selector switch 600, are illustrated.

The district selector switches have access to a plurality of groups of trunks outgoing to succeeding switches. In order that all subscribers lines may have access to any of these outgoing trunks through the district selector switches, it is necessary to multiple all trunks before all district switches. That is to say, each trunk in each grouplias .a corresponding appearance in each of the several district selector switches. The district selector switches may connect with groups of trunks of various characters leading in different directions. Some of these trunks may go to local switches while others may lead to distant offices. For the purpose of the present discussion, however, only those groups of trunks leading to the local switches will be specifically considered.

Assuming that the local exchange has a capacity of 10,000 subscribers lines, these lines may be divided into five terminal groups of 2000 lines each. Each terminal group of 2000 lines is served by a number of group selector switches 1200, and a number of connector switches 1300. The district acesose which lead directly to the switches of the terminal line groups. Hence, the several district switches are provided with five groups of trunks leading to the five different groups. These five groups of trunks appear in the district selector 500 in the vertical rows such as 503. 504, 505, 506 and 507.

The distrirt selector switche are equipped with horizontal link circuits or trunks 508, 509, 510, 511, etc., there being as many of these links as the capacity of the switch requires. For example, it is assumed that each of the district selector switches has of these link circuits divided into two sections, the upper and the lower sections of the switch, each section containing 35 links. Regarding selector switch 500, the upper sertion is represented by links 508, 509, 510,

511 and 512 while the lower section. is represented by links 513 and 517, inclusive. All incoming trunks103, 104. have access to all links in both sections and each link has access to one outgoing trunk in each of the vertical rows.

Depending upon the character of the group of outgoing trunks, said group may occupy all or a portion of a vertical row in either the upper or lower sections or it may occupy the entire vertical row. Where a small trunk group is suflicient, either the lower or upper'half of a given row may be used.

Consider as an example, .that'ea ch of the five terminal line groups requires a group of 35 trunks outgoing from the district sclector switch banks. The group of trunks leading to the first terminal group of 2000 lines which is assumed to be the one illus trated in the drawing, may occupy the upper half of the vertical row 507. The group of trunks leading to the second 2000 line group may appear in. the lower half of the vertical row 507. The-groups representing the third, fourth and fifth groups of 2000' lines may appear respectively in the upper and lower halves of the vertical row 506 and in the upper half of the vertical row 505. Other trunkgroups extending from the district selector switch 500 occupying the vertical rows 504, 503 may be used for any desired purpose such as interoflice calls.

As will be seen hereinafter, he common district marker mechanism controls selection at any of the district switches. Where each group of outgoing trunks appear in all switches and may be reached through any one of the switches under the control of the marker, it is essential'that every group of. trunks are multipled to all switches so as to have a corresponding appearance in all switches. With this provision, the marker will complete the selection in a given trunk group regardless of the district switch with which inc udes trunks 545 switches. Similarly, the trunks of the group appearing in the lower half of the vertical row 507 and including trunks 550, 551, 552 are multipled to ap er in the lower half of thevertical row 60 of switch 600 and cor- 'respondingly in all other "district switches.

The same is true of all other trunk groups.

There being a plurality of register senders, a district marker sender connector 700 consisting of a number of multi-contact relays 701, 702 and 703 is provided for connecting the difierent senders to the marker. The district marker shown 1n Figs. 8, 9

and 10, which is provided for the common use of a number of district switches, has for its function to receive part of the record initially established on the sender and to use this record to determine selection of a group of trunks at the district switch. The district marker includes a set of register relays 800 which receive the thousands record from the sender and determine the selection of the proper one of a number of group relays 900, 901, 902, etc. The district marker also comprises a set of testing relays including the two groups 1000 and 1001. The group of relays 1000 are used for testing the respective trunks 1n any group appearing in the upper section of the district selectors. The group of testing relays 1001 serve to test corresponding trunks in any group or vertical row appearmg m the lower section of the district selector switches. The testing relays also serve to test the condition of the horizontal links or trunks in any district switch.

The testing relays of the marker .are associated or connected with the different groups of outgoing trunks by means of multi-contact relay sets 905 and 906. For instance, the relay 909 serves to connect the group of relays 1000 to the testing wires of the group of trunks in the upper half of the vertical row 507 and multi-contact relay 912 servesto connect the group of testing relays 1001 with the test wires of the group appearing in the lower half of the vertical row 507. The other .multi-contact relays 908, 911, etc., serve similarly to connect the testing relays with the groups of trunks appearing in other vertical rows of the district switches. v

For connecting the testing relays of the marker with the test wires of the horizontal links of the district switches there are provided two sets of multi-contact relays 1110 and 1111. The relay 1101 connects the with several vertical rows group of testing rela s 1000 to the test wires of the respective lin s 508, 509, 510, etc., in the up r section of the district selector 500. elay 1103 connects the group of testing relays 1001 to the test wires of the respective links in the lower-section of the district switch 500. The other multi-contact relays 1102, 1104, etc;, serve to connect the common testing relays to the horizontal links in other district selector switches.

As hereinbefore explained, the terminal lme group of 2000 lines is served b a number of group selector switches an a number of connector switches. For the partlcular terminal group illustrated, one group selector 1200 and one connector 1300 are shown in the drawing. While these switches are only partially illustrated, it

will be understood that the group selector has a capacity for receiving any desired number of incoming trunks and is provided of outgoing trunks leading to the different connector switches 1300. It is also obvious that the connector switch 1300, which is only partially shown in the drawing, may have a capacity for receivingithe proper number of incoming trunks and a capacity for any desired number of outgoing subscribers mes.

Each of the five terminal line roups of 2000 lines is further provided with a line marker or controlling mechanism for determining selection at the group selector and connector switches. The line marker is provided with a sender connector 801 comprlslng a number of multi-contact relays 808, 809, etc., for connecting the marker with any oneof the register senders.

The line marker is equipped with two thousands register relays 1418, 1419 and with the hundreds, tens and units registers 1400, 1401, and 1402, respectively. which receive the numerical record from the register sender. Moreover, the line marker has a translator'mechanism 1404, and 1403 which cooperates with the registers to determine the selective operations. There is also provided in the line marker, 9. set of common testing relays 802, for testing the trunks interconnecting the group selector and connector switches.

As above mentioned, the selector switch ing devices employed in this system are of the coordinate type comprising intermediate or link circuits for connectin incoming lines to outgoing lines. The structure of the switch includes briefly a number of 7 ment of the connection which is held solely by the horizontal bar after the vertical bars are released. For a complete description of the structure of a switch of this character, reference is made to the patent to S. B. Williams,.No. 1,517,331, issued December 2, 1924, and to the British patent to Western Electric Company, Limited, No. 183,438, accepted September 6, 1923.

Detailed desme'ptz'on of establishment of a connection.

Consider that the subscriber of line 101 desires to hold a conversation with the subscriber of the line 1316 appearing in the same central ofiice. It may-also be assumed that the directory number of the subscribers line 1316 is 1234. The initiation of the call on the calling subscribers'line causes the operation of the line switch 100 whereby the line is extended over an idle link 115 to idle trunk 103 extending to the district selector switch 500. Furthermore, the initiation of the call causes the operation of the sender selector switch 200 and the calling subscribers line is extended over the link circuit 202 and the circuit 204 to the idle register sender shown in the drawing. Had the sender illustrated been busy, the subscribers line would be extended over another circuit such as the circuit 205 leading to another sender, not shown. For an understanding of the manner in which callin lines are extended to idle trunks, and to idle senders, through line switches and sender selectors of the coordinate type, reference is made to the patent to S. B. Williams above mentioned, No. 1,517,331. During the operation of the sender selector switch 200, a circuit may be closed v in any suitable manner for the relay 105.

Relay 105 operates and closes a circuit from battery throu h the winding of slow-to-release relay 10 to ground at theinner left contact of relay 105. Relay 107 places ground on the sleeve conductor 116 of the trunk 103. Relay 105 in operating, extends the tip and ring conductors of the trunk 103 through the sender selector 200 to the register sender mechanism. An impulse circuit is thereupon completed as follows: battery through the resistance 31 8, winding of impulse relay 300, outer left contact of relay 303, conductor 319 through contacts of the sender selector switch 200, conductor 208, inner right contact of relay 105 thence'over the ring conductor of trunk 103 throu 11 contacts of the line switch 100 over the su scribers line and returning over the tip conductor through the line switch 100, outer right contact of relay 105, conductor 209, through contacts of the selector switch 200,

1 conductor 320, inner left contact of relay 303, winding of the balancing coil 301 to ground. The impulse relay 300 operates and closes a circuit for the slow-to-release relay 302. Relay 302 completes a circuit from ground throughits left contact, conductors. 321, 32% through contacts of the switch 200, conductor 210, winding of relay 105 to battery. Relay 105 is held'in this circuit under the control of the relay 302 in the sender. Relay 302 also completes the circuit from ground through its contact over conductor 321, left contact of relay 305, left back contact of relay 304, winding of slow-to-release rela 306 to battery. Relay 306 operates in this circuit.

The apparatus is now in condition for receiving the first series of impulses. The calling subscriber manipulates his impulse transmitter to send the first series, in the present case consisting of a single impulse. at the time the relay 302 operates it closes a circuit from batter resistance 339, through the left hand winding of relay 307 to ground at the right hand contact of said .lay 307 closes a circuit from battery through the winding of relay 304, outer left contact of relay 307 to ground over conductor 321. Relay 304 operates and locks in a circuit through its left front contact, left contact of relay 305, to the grounded conductor 321. Relay 304 opens the original circuit of relay 306. The latter relay now is energized in a circuit traceable through the outer right contact of relay 307 to ground over conductor 321.

Relay 307 closes a circuit through the left hand winding of relay 308 to ground at the inner left contact of relay 307. Relay 308 operates and closes a circuit from battery through its right hand winding and inner right contact to the grounded conductor 321; Relay308 in operating, completes a circuit through its left hand winding and left contact, conductor 324, outer right back contacts of counting relays 315, 314, 313 and 312 in series, winding of relay 312, outer left back contact of relay 313, conductors 325 and 326,0uter right contact of relay 305, left front "contact of relay 304, left contact of relay 305 to ground over conductor 321. So long as the relay 307 re mains operated, however, relay 312 is shunted and does not receive suflicient current in the circuit traced to operate. end of the impulse, the subscribers line is closed, relay 300 operates and shunts relay 307 and this latter relay releases, opening At the V the original circuit through the left hand relay 308. Relay 312 locks in a circuit, from battery over conductor 327, inner right contact of relay 312, winding of said relay, left back contact of relay 313 to ground over conductor 325.

It should be noted at this point that the armatures of the counting relay 312, and this is true of the remaining counting relays, are so arranged that the inner right contact is closed slightly in advance of the opening of the outer right back contact. By this arrangement, the locking of the relay is sure to opuciur before the energizing circuit is open 4 Immediately that the relay 312 opens its back contact the circuit through the left hand winding of relay 308 is opened. Relay 308 is wound difl'erentially and hence when the left hand winding is opened, the

effect of the right hand winding is to cause a quickerrelease. After an interval has elapsed following the impulse series, the slow-to-release relay'306 retracts its armature. A circuit now leads from ground over conductor 321, contact of relay 306, right contact of relay 304, inner right contact of relay 305, conductor 328, right back contact of relay 408, winding of relay 407 to battery. Relay 407 operates and connects the control leads from the counting relays through to the thousands register 400. Relay 407 also completes a circuitfrom battery through its winding and inner upper contact, conductor 426, winding of relay 305, right contact of relays 304 and 306 to the grounded conductor 321. Relay 305 does not operate at this time since its winding is shunted by the path previously traced through the winding of relay 407.

With relay 407 operated andthe first counting relay 312 energized, a circuit is closed from ground over conductor 326, conductor 325, outer left front contact of relay 312, conductor 329, outer right back contact of relay 317, conductor 330, lowermost contact of relay 407, windings of rela s 404 and 406'to battery. A branch circuit a so extends by way of conductor 427 through the windin of relay 423 to battery. These relays a1? operate and lock in circuits traceable through the inner left contact of relay 404, conductor 428to the holding conductor 321. Relay 406 completesa circuit from battery through the winding of relay 408 to the grounded conductor 428. Relay 408 operates and looks through its inner left contact. Relay 408 opens the shunt around the winding of relay 305 and this later relay operates in series with relay 407. Relay 305 opens the holding circuit of relay 304 and relay 304 releases to in turn open the circuit of relays 305 and 407. Relay 407 releases and disconnects the control leads from the registers.

The subscriber next manipulates his impulse transmitter to send the second. series of impulses representing the second digit. The control circuit operates in the manner described by the first im ulse and when the second impulse is receive a circuit is closed from battery through the left hand winding and left contact of rela 308, conductor 324 through the outer rig t back contacts of relays 315, 314 and-313 in series, outerright front contact of relay 312, winding of relay 313, outer left back contact of relay 314 to ground over conductor 325. Relay 313 operates and locks from battery over conductor 327 through its inner right contact and winding, outer left back contact of relay 314 to ground over conductor 325. Relay 313 at its outer left back contact opens the circuit of relay 312 and relay 312 releases.

After the proper interval has expired following the second series of impulses, relay 306 again becomes deenergized and a circuit is closed as follows: ground over conductor 321, right contacts of relays 306 and 304 inner right contact of relay 305, conductor 328, right front contact of relay 408, right back contact of relay 412, winding of relay 411, to battery. .Relay 411 operates and closes a circuit from battery through its winding and inner upper contact, conductors 430 and 426 winding of relay 305 and thence to ground as traced. Relay .305, however, being shunted remains inert until relay 412 is operated. Relay 411 operates and extends the control conductors through to the second register 401.

With relay 411 operated and with the second counting relay 313 actuated, a circuit is'completed' from ground over the conductor 326 as hereinbefore traced, conductor 325, outer left front contact of relay 313, conductor 331, next to the lower contact of relay411, winding of register relay 410 to battery. Relay 410 operates and looks through its winding and inner left contact to ground over conductors 431 and 421. Relay closes a circuit from battery through the winding of relay 412, outer left contact of relay 410, to ground over conductor 431. Relay 412 becomes energized and locks through its winding and left contact to the grounded conductor 321. Relay 412 opens the shunt around the winding of relay 305 and rela 305 operates in series with relay 411. Re ay 305 opens the circuit of relay 304 and relay 304 releases to open the circuit of relay 305 and relay 411. Relay 411 disconnects the counting relays from the register 401. The impulse receiving circuit is now in condition for the next series of impulses. r l

The subscriber next transmits the third series consisting of three impulses representing the third digit of the wanted number. The first two impulses cause the operation of counting relays 312 and 313 and the release of relay 312. Upon the transmission of the third impulse, a circuit is completed through the left hand winding of relay 308 over conductor 324 through t e outer right back contacts of relays 315 and 314 outer ri ht front contact of relay 313, winding of relay 314, outer left back contact of relay 315 to ground over conductor 325. Relay 314 operates and looks through its inner right contact and winding and through the outer left contact of relay 315 to the grounded conductor 325. Relay 314 opens the circuit of relay 213. Relay 314 also opens the .circuit' of theleft hand winding of relay 308 and this relay being differentiated releases immediately. After the elapse of a giveninterval fo owing the third 'im ulse,

the slow relay 306 becomes deenergize and 'the circuit hereinbefore traced is closed by' way of conductor 328 through the right front contaizts of relays 408 and 412, right back contact" of relay 416, winding of re a 415 to battery. Relay 415 operates an closes a circuit to battery through its winding and inner upper contact over conductors 430 and 426 through the winding of relay 305 as traced to ground, Relay 305 does not 0 crate at this time.

' With re ay 415 and relay 314 operated, a circuit may be traced from ground over conductor 326 through the outer left front contact of relay 314, conductor 330, lowermost contact of relay 415, winding of relay 413 to battery. Another circuit is closed from ground over conductor 326 through the inner left contact of relay 314, conductor 331, next .to the lower contact of relay 415,'winding' of relay 414 to battery. Re-

, of relay 304 whereupon relays 305 'and 415 v are deenergized, and the sender is placed in condition for receiving the last. series of impulses.

The calling subscriber sends the last series of four impulses in response to the first three of which relays 312, 313 and 314 are operated in succession and -rela s 312 and 313 are released in succession. e fourth impulse causes the operation of relay 308 and the previously traced circuit is closed from batterythrough the left hand winding of this relay over conductor 324 hence through the outer right back contact of re-' lay 315, outer right front contact of relay 414, winding of relay 315, outer left bac contact of rela "316 to ground over conductor 325. Re ay 315 operates and. looks through its inner right contact and winding and the outer left back' contact of relay 316 to the ounded conductor 325. Relay the circuit through the left hand winding of relay 308. -Re1ay 308 is then released. After an interval has expired, slow relay 306 releases and the circuit already traced is completed from ground over conductor 328 through the right front contacts of relays 408,412, and 416 right contact of relay 420, winding of relay 419 to battery. Rela from'the counting relays through to the units register 403, and also closes a circuit throu h its winding and inner upper con- ,tact t once over conductor 430 as hereinbefore traced throu h the winding of relay 305 to ground. Re ay 305, however, being shunted does not operate at this time.

With relay 419 and relay 315 operated, a circuit is completed from ground over conductors 326 and 325 through the outer left back contact of relay 312, inner left contact ner lower contact of relay-419, winding of register relay 433 "to battery; Relay 433 locks through its inner left contact to ground over conductors 434 and 321. Relay 433 closes a circuit from battery through the winding of relay 420, outer left contact of relay 433 to the ounded conductor 434. Relay 420 removes t e shunt from the winding of relay 305 and this latter relay operates in series with relay 419. Relay 305 in the manner explained, causes the release. of relay 304 which in turn causes the release of relays 305 and 419.

As soon as the first or thousands digit is recorded on the re ister'400, the sender is connected to the district marker in order that the record of the thousands digit may be transferred to the register 800 for determining the group selective operation at the district. switch. This operation takes place immediately without waiting 'for the subscriber to send the remaining series of impulses. Vhcn relay 408 operates, it completes a circuit from battery through the 315 opens t 1e circuit of relay 314 and also 419 operates, extending the control lea s 'of relay 315, conductor 332, next'tothe in- 7 winding of relay 309, conductor 333, outer left contact of relay 408, conductors 428 and 321 toground at the left contact of relay 302. Belay 309 attracts its armature andcloses a circuit over the grounded conductor 321, outer left back contact of relay 311, 1

contact of relay 309, conductor 334, winding of relay 709 to battery. Relay 709 opcrates and completes a circuit from ground through its ri ht contact, conductor 716, right contact 0 relay 711, winding of relay 712 to battery. Relay 712 operates and a 

